Purpose: Examine the association of visits to the natural environment, connectedness to nature, physical activity, and the adoption of pro-environmental behaviors (PEBs) in individuals aged 18 years or older. Design: Cross-sectional study. Setting: City of Vila Real, located in the north of Portugal. Subjects: We recruited 194 individuals (61 men and 133 women) aged 18-75 years. Mesures: A self-administered questionnaire was used to measure nature visits, connectedness to nature, PEBs, and demographic characteristics. Neighborhood green space was appreciated through a Simplified Land Occupation Map and physical activity was measured using ActiGraph accelerometers (wGT3X-BT). Analysis: Correlations and nonlinear canonical correlation analysis were used to analyze the data. The coefficients of canonical and multiple correlations were calculated. Results: Nature visits were associated with involvement in environmental volunteering (V = .317, P ≤ .05) among men. In these, higher levels of moderate-vigorous PA were associated with green travel behavior (η ² = .325, P ≤ .05). Connectedness with nature was related (P ≤ .05) to private sphere behaviors, such as purchase of eco-products (η2 = .191) and local/seasonal products (η2 = .186) in females and encouraging care and protection of natural environment (η2 = .336, P ≤ .01) in males. Conclusions: Nature visits, connection to nature, and physical activity levels were related to the adoption of PEBs in the private and public sphere, and these relationships differed between men and women.